libcpp: Improve location for macro names [PR66290]

When libcpp reports diagnostics whose locus is a macro name (such as for
-Wunused-macros), it uses the location in the cpp_macro object that was
stored by _cpp_new_macro. This is currently set to pfile->directive_line,
which contains the line number only and no column information. This patch
changes the stored location to the src_loc for the token defining the macro
name, which includes the location and range information.

libcpp/ChangeLog:

	PR c++/66290
	* macro.cc (_cpp_create_definition): Add location argument.
	* internal.h (_cpp_create_definition): Adjust prototype.
	* directives.cc (do_define): Pass new location argument to
	_cpp_create_definition.
	(do_undef): Stop passing inferior location to cpp_warning_with_line;
	the default from cpp_warning is better.
	(cpp_pop_definition): Pass new location argument to
	_cpp_create_definition.
	* pch.cc (cpp_read_state): Likewise.

gcc/testsuite/ChangeLog:

	PR c++/66290
	* c-c++-common/cpp/macro-ranges.c: New test.
	* c-c++-common/cpp/line-2.c: Adapt to check for column information
	on macro-related libcpp warnings.
	* c-c++-common/cpp/line-3.c: Likewise.
	* c-c++-common/cpp/macro-arg-count-1.c: Likewise.
	* c-c++-common/cpp/pr58844-1.c: Likewise.
	* c-c++-common/cpp/pr58844-2.c: Likewise.
	* c-c++-common/cpp/warning-zero-location.c: Likewise.
	* c-c++-common/pragma-diag-14.c: Likewise.
	* c-c++-common/pragma-diag-15.c: Likewise.
	* g++.dg/modules/macro-2_d.C: Likewise.
	* g++.dg/modules/macro-4_d.C: Likewise.
	* g++.dg/modules/macro-4_e.C: Likewise.
	* g++.dg/spellcheck-macro-ordering.C: Likewise.
	* gcc.dg/builtin-redefine.c: Likewise.
	* gcc.dg/cpp/Wunused.c: Likewise.
	* gcc.dg/cpp/redef2.c: Likewise.
	* gcc.dg/cpp/redef3.c: Likewise.
	* gcc.dg/cpp/redef4.c: Likewise.
	* gcc.dg/cpp/ucnid-11-utf8.c: Likewise.
	* gcc.dg/cpp/ucnid-11.c: Likewise.
	* gcc.dg/cpp/undef2.c: Likewise.
	* gcc.dg/cpp/warn-redefined-2.c: Likewise.
	* gcc.dg/cpp/warn-redefined.c: Likewise.
	* gcc.dg/cpp/warn-unused-macros-2.c: Likewise.
	* gcc.dg/cpp/warn-unused-macros.c: Likewise.

libcpp/directives.cc

@@ -655,6 +655,10 @@ do_define (cpp_reader *pfile)
 
   if (node)
     {
+      /* This is a better location than pfile->directive_line to store
+	 as the macro location.  */
+      const location_t name_loc = cpp_diagnostic_get_current_location (pfile);
+
       /* If we have been requested to expand comments into macros,
 	 then re-enable saving of comments.  */
       pfile->state.save_comments =
@@ -663,7 +667,7 @@ do_define (cpp_reader *pfile)
       if (pfile->cb.before_define)
 	pfile->cb.before_define (pfile);
 
-      if (_cpp_create_definition (pfile, node))
+      if (_cpp_create_definition (pfile, node, name_loc))
 	if (pfile->cb.define)
 	  pfile->cb.define (pfile, pfile->directive_line, node);
 
@@ -694,9 +698,8 @@ do_undef (cpp_reader *pfile)
 		       "undefining \"%s\"", NODE_NAME (node));
 	  else if (cpp_builtin_macro_p (node)
 		   && CPP_OPTION (pfile, warn_builtin_macro_redefined))
-	    cpp_warning_with_line (pfile, CPP_W_BUILTIN_MACRO_REDEFINED,
-				   pfile->directive_line, 0,
-				   "undefining \"%s\"", NODE_NAME (node));
+	    cpp_warning (pfile, CPP_W_BUILTIN_MACRO_REDEFINED,
+			 "undefining \"%s\"", NODE_NAME (node));
 
 	  if (node->value.macro
 	      && CPP_OPTION (pfile, warn_unused_macros))
@@ -2642,7 +2645,7 @@ cpp_pop_definition (cpp_reader *pfile, struct def_pragma_macro *c)
       {
 	_cpp_clean_line (pfile);
 	nbuf->sysp = 1;
-	if (!_cpp_create_definition (pfile, h))
+	if (!_cpp_create_definition (pfile, h, 0))
 	  abort ();
 	_cpp_pop_buffer (pfile);
       }

libcpp/internal.h

@@ -686,7 +686,7 @@ inline bool _cpp_maybe_notify_macro_use (cpp_reader *pfile, cpp_hashnode *node,
 }
 extern cpp_macro *_cpp_new_macro (cpp_reader *, cpp_macro_kind, void *);
 extern void _cpp_free_definition (cpp_hashnode *);
-extern bool _cpp_create_definition (cpp_reader *, cpp_hashnode *);
+extern bool _cpp_create_definition (cpp_reader *, cpp_hashnode *, location_t);
 extern void _cpp_pop_context (cpp_reader *);
 extern void _cpp_push_text_context (cpp_reader *, cpp_hashnode *,
 				    const unsigned char *, size_t);

libcpp/macro.cc

@@ -3819,7 +3819,8 @@ _cpp_new_macro (cpp_reader *pfile, cpp_macro_kind kind, void *placement)
 
 /* Parse a macro and save its expansion.  Returns nonzero on success.  */
 bool
-_cpp_create_definition (cpp_reader *pfile, cpp_hashnode *node)
+_cpp_create_definition (cpp_reader *pfile, cpp_hashnode *node,
+			location_t name_loc)
 {
   cpp_macro *macro;
 
@@ -3831,6 +3832,13 @@ _cpp_create_definition (cpp_reader *pfile, cpp_hashnode *node)
   if (!macro)
     return false;
 
+  /* _cpp_new_macro () has set macro->line to pfile->directive_line, which
+     denotes the line containing the #define with no column information.  If
+     provided, change to name_loc, which will be the token src_loc for the
+     macro name, including the location and range information.  */
+  if (name_loc)
+    macro->line = name_loc;
+
   if (cpp_macro_p (node))
     {
       if (CPP_OPTION (pfile, warn_unused_macros))
@@ -3844,7 +3852,7 @@ _cpp_create_definition (cpp_reader *pfile, cpp_hashnode *node)
 
 	  bool warned = 
 	    cpp_pedwarning_with_line (pfile, reason,
-				      pfile->directive_line, 0,
+				      macro->line, 0,
 				      "\"%s\" redefined", NODE_NAME (node));
 
 	  if (warned && cpp_user_macro_p (node))

libcpp/pch.cc

@@ -838,7 +838,7 @@ cpp_read_state (cpp_reader *r, const char *name, FILE *f,
 	      != NULL)
 	    {
 	      _cpp_clean_line (r);
-	      if (!_cpp_create_definition (r, h))
+	      if (!_cpp_create_definition (r, h, 0))
 		abort ();
 	      _cpp_pop_buffer (r);
 	    }